Footwear brand Allbirds uses merino wool to manufacture the textile uppers of its Wool Runners shoes, which also feature laces made from recycled plastic bottles and insoles produced using castor bean oil.
Allbirds co-founder Tim Brown was disappointed with the synthetic materials used to manufacture most footwear and set out to develop an alternative that is both more comfortable and more sustainable.

The London-based New Zealander spent several years researching ways of producing shoes using merino wool, which is popular in his home country because of its luxurious softness, breathability and insulating properties.
Brown teamed up with engineer and renewables expert Joey Zwillinger to develop a wool fabric that could be used specifically for making shoes. Following a development process that involved creating between 60 and 80 prototypes, the company settled on a design that it claimed is "intentionally minimalist" and features "no senseless details".

The company sold $1 million worth of shoes in its first month of trading, and the Wool Runners were described by TIME magazine as "The World's Most Comfortable Shoe". The shoe also features on the longlist for the Dezeen Awards 2019 in the wearable design category.
Allbirds worked with a specialist Italian mill to develop the proprietary dual-faced wool textile, which is soft to the touch, machine washable and durable enough for use in footwear.
The wool textile is used for the upper of the sh...